The poll loop was storing msg.ID (UUID string) as afterID, but the server
expects the integer queue cursor from last_id. This caused the CLI to
re-fetch ALL messages on every poll cycle.
- Change PollMessages to accept int64 afterID and return PollResult with LastID
- Track lastQID (queue cursor) instead of lastMsgID (UUID)
- Parse the wrapped MessagesResponse properly
The bare 'chatd' pattern matched the cmd/chatd/ directory,
preventing main.go from being tracked. Use /chatd to only
match the binary at the repo root.
